Measurement of the x-ray absorption properties of a material near the ionization energy can reveal information about the chemical state of the elements of interest within a sample, revealing information such as oxidation state and coordination number.
X-ray absorption spectroscopy (XAS) measures the fraction of x-rays absorbed by an object as a function of x-ray energy over a predetermined narrow energy range. It is often carried out at synchrotron light sources because of their high brightness and energy tunability. Unfortunately, synchrotron based x-ray absorption spectroscopy systems have numerous accessibility limitations, such as long wait times to obtain proposal-based access, limited measurement time granted per user group, and logistic issues including the need for travel and shipment of special experiment.
Small laboratory-based x-ray absorption spectroscopy systems would provide easy access and full control, however the performance of laboratory XAS systems has been largely limited by a combination of many factors, including low brightness and flux of laboratory x-ray sources, low efficiency of the x-ray optic used, and low diffraction efficiency of the crystal analyzer associated with the use of high index reflections required for high energy resolution measurements due to the typically large x-ray source sizes of laboratory sources. Those limitations result in unacceptably long acquisition times (tens of hours) and/or poor energy resolution. As a result, there are few laboratory systems in use.
There is a need for a laboratory x-ray absorption spectroscopy system with high throughput that circumvents the limitations of prior laboratory XAS systems.